Blanket clamp for blanket cylinders of printing presses



Dec. 11, 1951 OF PRINTING PRESSES Filed -May* 15, 1948 4 sheets-sheet `1 MW QW R 5 m @E 01W my AM bn WM mh mw 1M wh Nw .Y A k m @A H www w R. l@ mw 1 /Vf E NN .wb Nn m5 b h Q QN QT| hTT mw Bil t--- $11.11. vv n .n l1 h. l n w H NAM. LWN NNW) NW .11 .1T 1 1 n. mw nw mm.v N M l|||1| lll I A lt H l HH Q Q QN Q .Q M

Dec. 11, 1951 2,578,406

O. V. DUTRO BLANKET CLAMP FOR BLANKET CYLINDERS 0F PRINTING PRESSES Filed May 15, 1948 4 Sheets-Sheet 2 INVENTOR.

HV/LLE VDL/T510 ATTURAEYS CYLINDERS ES O. DUTRO BLANKET CLAM BLANKET NTING PRESS Dec. 11, 1951 4 Sheets-Sheet 3 Filed May 15, 1948 INVENTOR. UH V/LLE /UU THU B @Wy :0

4 TTUHNEYE Dec. 1l, 1951 o. v. DUTRO BLANKET CLAMP FOR BLANKET CYLINDERS OF PRINTING PRESSES 4 Sheets-Sheet 4 Filed May l5, 1948 m M wx QN .Q R. W Mw m mlm m Y .9v Wmv m 1 l l n l l x x lr ww, WV M N l M W H i :1--- .m A mm om. H l rl Q* WMWWII 0MM HU U atented Dec. 11, 195.1

BLAN KET CLAMP FOR BLAN KET CYLINDERS OF PRINTING PRESSES Orville V. Dutro, La Canada, Calif., assigner to Time, Inc., New York, N. Y., a corporation of New York l Application May 15, 1948, Serial No. 27,208

3 Claims.

The present invention relates to blanket cylinders for offset printing presses and embodies, more specifically, an improved form of blanket cylinder wherein the blanket is effectively clamped in its printing position upon the blanket cylinder and maintained therein effectively during the printing operation.

Existing blanket clamp mechanisms necessitate the use of so-called blanket irons, which are metal strips fastened to the ends of the blanket, and are used for the purpose of connecting the blanket to the locking mechanism. These blanket irons have to be screwed, clamped, or otherwise attached to the rubber blanket before the blanket is put on the cylinder, and it is an object of this invention to provide a mechanism for engaging the blanket ends directly, rather than necessitating the use of blanket irons.

Another object of the present invention is to provide a blanket cylinder for offset printing presses having means embodied therein for effectively clamping the blanket in printing position upon the printing cylinder, the clamp mechanism being designed to place the blanket under a uniform and controlled tension and effectively secured under such condition.

Yet another object of the invention is to provide a blanket clamp mechanism of the above character wherein the blanket may be clamped in printing position upon the printing cylinder by a single operation, such operation serving to maintain the blanket securely in position under the desired condition of tension during the printing operation.

Further objectsof the invention will be apparent as it is described in greater detail in connection` with the accompanying' drawings, wherein Figure 1 is a plan view of a blanket cylinder constructed in accordance with the present invention;

Figure 2 is a view in section, taken on line 2-2 of Figure 1, and looking in the direction of the arrows;

Figure 3 is a view in section, taken on line 3-3 of Figure 2, and looking in the direction of the arrows;

Figure 4 is a view in section, taken on lined-4 of Figure 3, and looking in the direction of the arrows; y

Figure 5 is an enlarged partial view in section, taken on line 5-5 of Figure 1, and looking in the direction of the arrows;

Figure 6 is an enlarged partial view in section, taken on line 6-6 of Figure l, and looking in the direction of the arrows;

(Cl. lOl-415.1)

Figure 7 is a View in section, taken on line I--T of Figure 1, and looking in the direction of the arrows;

Figure 8 is a View in section, taken on the broken line 8-8 of Figure 5, and looking in the direction of the arrows; and

Figure 9 is a view on section, taken on line 9-9 of Figure l., and looking in the direction of the arrows, this view illustrating means for clamping one end of the blanket in the cylinder.

Referring to the above drawings and particularly to Figure l, the side frame members of a printing press are shown at l0 and II, the members being formed with bearings I2. A blanket cylinder is illustrated at I3 and is provided with a shaft I4, the ends of which are journaled in the bearings I2. The ends I5 and I6 of the blanket cylinder I3 are formed as continuous circular sections between which a blanket receiving cylinder portion I1 is formed. The cylinder portion I1 is provided with a circular hollow portion I8 (Figures 5 and 6) extending across the length thereof and having a slotted extension I9 within which the ends of a blanket 20 are adapted to be received. The cylindrical section il is further rabbeted at 2l to receive a cylindrical segment 22 that is secured in position by means of bolts 23. The segment 22 becomes a permanent part of the cylinder and its peripheral surface 24 is concentric with the peripheral surface 25 of section Il, the segment 22 being provided merely for the purpose of facilitating the formation of the slot I9 hereinabove mentioned.

Slot I9 is formed with one side 26 that tapers inwardly to meet the cylindrical surface of the bore I8 and thus forms a camV surface for the purpose hereinafter described. As will be later described, the side 2S is formed by the mechanism which clamps one end of the blanket 20.

Within the bore I8 a shaft 2l is received, the shaft being formed with an elongated bearing shoe 28 that maintains the shaft at all times coaxial with the bore IS, and diametrically opposed to the shoe 23, the shaft is formed with longitudinally extending teeth 29. Jaws 30 are received within the bore I8 adjacent the teeth 29 and are formed Iwith pivot extremities 3| that are received within a circular bore 32 formed within shaft 2l. The jaws 30 are formed with teeth 33 that cooperate with teeth 29 in order to grip the extremity 34 of the blanket 2B in the position illustrated in Figure 6.

As illustrated in Figure 7 the jaw sections 3l) are loosely connected together by means of pins 36 in order that they may all be moved simultaneously, but, due to the looseness of one end of each pin 36 within the hole formed in the adjacent jaw section, the several jaw sections can individually adapt themselves to the clamping of the blanket, which insures uniform grip along the cylinder. The end jaw sections 31 and 38 are formed with curved cam ledges 39 (Figure 5) that are adapted to engage guide pins 40 in order to move the jaws 30 to the open position when the shaft 21 is turned to the extreme release position. The extremities of shaft 21 are formed with elongated recesses 4I in order to receive the pins 40 and prevent interference between the pins and shaft during rotation of the shaft 21 to the locked position, as illustrated in Figure 5.

The ends of shaft 21 are formed with stub shafts 42 and 43 (Figure '7), these stub shafts being journaled in the end sections I5 and I6, respectively. Stub shaft 42 is provided with a worm gear 44 which may be operated by a suit-'- able worm, and stub shaft 43 is provided with a squared end 45. Between the worm gear 44 and the end section I5, a collar 45 is secured to the stub shaft 42, this collar having a cutaway prtion 41, as illustrated in Figure 4. A limit pin 48 is carried by the end section I and is received within the cutaway portion 41, thus to limit the rotation of the shaft 21 between certain desired extremes.

As illustrated in Figure 2, the worm gear 44 is driven by means of a worm shaft 45 that is journaled in a bracket 50 carried by the end section I5 and also in the end shaft i4, the outer extremity of the worm 49 being provided with a squared end 5I in order to enable the worm to be rotated for the purpose of adjusting and rotating the shaft 21.

With reference to Figures 5 and d, it will be seen that the outer surfaces of the jaws 33 are formed with rounded noses 52 that engage the cam surface 26. When the shaft 21 is moved in a clockwise direction to its extreme position, the flange plates 39 engage the pins 4Q and cause the jaws to open. The cam surface 25 diverges sufficiently to permit the jaws to open far enough to receive the end 34 of the blanket 20.

Beneath the segment 22, and extending laterally across the cylinder, a quoin mechanism is provided as illustrated in Figure 9. This mecha# nism utilizes a fixed plate 53 having a plurality of wedge blocks 54 formed therein and against which slide plate 55, having wedge blocks 56 formed therein, are adapted to slide. Movement of the plate 55 is accomplished by means of stub shafts 51`having fingers 58 that are adapted to engage the ends of plate 55. The shafts 51 are formed with threaded portions 59 that are threaded in sleeve 60 secured in the ends I5 and i6 of the cylinder by means of retainer rings 6I. A cylindrical fitting 32 having recesses 53 formed therein is keyed to the sleeve 0B and is adapted to receive a Spanner wrench in order that it may be turned. Keys 64 limit the movement of the stub shafts 51 to longitudinal movement, as viewed in Figure 9, and in this fashion the lateral position of the plate 55 with respect to plate 53 is varied.

The plate 53 is formed with clamping teeth 65 (Figure 6), and these teeth are adapted to engage one end of the blanket 20.

The mechanism is utilized in the following manner. One end of the blanket 20 is secured under the teeth 65 on the plate 53 and the vplate tween the teeth above mentioned.

is then moved to cause the teeth to securely end gage and clamp that end of the blanket. The other end of the blanket is then inserted between the teeth 29 and 33, the latter being formed on the jaws 30. As previously described, when the shaft 21 is rotated in a clockwise direction, as viewed in Figure 6, the jaws 33 open and facilitate the insertion of the end of the blanket berIhe outer end of the plates 53 and 55 are curved to form the cam surface 26 and, after the end of the blanket is inserted between the teeth 29 and 33, the shaft 21 is rotated in a counter-clockwise direction to effect the clamping of the end of the blanket and the stretching of the blanket over the blanket cylinder, as illustrated in Figure 6.

From the foregoing it will be seen that an effective blanket clamp has been provided for a blanket cylinder mechanism. The tension in the blanket, as well as its attachment and release, is effectively obtained and maintained at all times.

While the invention has been described with specific reference to the structure shown in the accompanying drawings, it is not to 'be limited save as defined in the appended claims.

I claim:

l. A blanket cylinder for an offset printing press comprising a cylinder adapted to be journaled in a press frame, a quoin mechanism in the cylinder for clamping one end of a flexible blanket, said quoin mechanism comprising a blanket gripping plate and wedge means for actuating said gripping plate, a shaft rotatably mounted in the cylinder, means to turn the shaft, means pivoted on the shaft adapted to clamp the other end of a flexible blanket, and a cam surface formed on the quoin mechanism to actuate the pivoted clamp means upon turning the shaft.

2. A blanket cylinder for an offset printing press comprising a cylinder adapted to be journaled in a press frame, a shaft rotatably mounted in the cylinder, means to turn the shaft, clamp means pivoted on the shaft, and a cam surface formed on the blanket cylinder to actuate the pivoted clamp means upon turning the shaft.

3. A blanket cylinder for an offset printing press comprising a cylinder adapted to be journaled in a press frame, a cylindrical bore formed in the cylinder adjacent its periphery, a slot connecting the bore with the cylinder periphery, a shaft rotatably mounted in the bore, means to turn the shaft, clamp means pivoted on the shaft, cooperating jaws on the shaft and clamp means actuated by a cam .surface formed on the blanket cylinder to actuate clamp means upon turning the shaft.

ORVILLE V. DUTRO.

REFERENCES CITED The following references are of Yrecord in the le of this patent:

UNITED STATES PATENTS Number Name Date 935,439 lWhite Sept. 28, 1909 1,090,664 Wait Mar. 17, 1914 2,105,452 Busk Jan. ll, 1938 v2,123,997 JirousekV July 19, 1938 2,236,230 Worthington Mar. 25, 1941 2,320,239 Huck May 25, 1943 

